1. Field of the Invention
The present invention relates to a portable self-contained inflatable, multi-cell flexible and hermetically sealed air cushion device. The air cushion device can be asymmetrically contoured on demand to conform to and support an irregularly shaped load applied to both faces of the cushion. In particular, the invention relates to the application of this principle in the construction of contourable pneumatic portable back support cushions. The cushion is usable in combination with existing seating in the same manner as conventional stuffed portable back cushions which require an existing substrate for support. Such substrate would normally be the back of any existing seating means such as an upholstered chair, car seat, patio chair or the like.
2. Description of the Prior Art
Conventional prior art portable back cushions are usually of the stuffed or padded variety and provide a passive support to the user. As a passive support, these cushions flatten out and are impressed into the substrate or seat back under the weight of the user without necessarily providing the desired lumbar support. With these cushions, the greater the weight of the user, the less effective the cushion becomes in providing back support.
In addition to the conventional stuffed cushion, multi-cell pneumatic cushions with control air conduits which provide a certain amount of contouring are known in the prior art. An example of such contourable pneumatic cushions is found in my prior U.S. Pat. No. 3,192,541 entitled CONTOURABLE PNEUMATIC CUSHIONS. My prior patent discloses a cushion in which the communicating air conduits and the contour control valve are arranged externally from the cushion cells and are constructed as an appendage thereto while operating in a hermetically closed cycle. The present invention constitutes an improvement in the concept, utility, operation and construction of my prior patent.